【學術】Cerebral Venous Thrombosis

Introduction

• Cerebral venous thrombosis is located in descending order in the following venous structures:
• Major dural sinuses:
  Superior sagittal sinus, transverse, straight and sigmoid sinuses.
• Cortical veins:
  • Vein of Labbe, which drains the temporal lobe.
  • Vein of Trolard, which is the largest cortical vein that drains into the superior sagittal sinus.
• Deep veins: 
• Internal cerebral and thalamostriate veins.
• Cavernous sinus.

Clinical presentation

• Clinically patients with cerebral venous thrombosis present with variable symptoms ranging from headache to seizure and coma in severe cases.
• In adults, coagulopathies is the cause in 70% and infection is the cause in 10% of cases.
• In women, oral contraceptive use and pregnancy are strong risk factors.

Image

• Dense clot sign
• Direct visualization of a clot in the cerebral veins on a non enhanced CT scan is known as the dense clot sign. It is seen in only one third of cases.

• Empty delta sign
• The sign consists of a triangular area of enhancement with a relatively low-attenuating center, which is the thrombosed sinus. The likely explanation is enhancement of the rich dural venous collateral circulation surrounding the thrombosed sinus, producing the central region of low attenuation. 

• Absence of normal flow void on MR
• T2-weighted image with normal flow void in the right sigmoid sinus and jugular vein (blue arrow). On the left there is abnormal high signal as a result of thrombosis (red arrow).

【學術】Deep Vein Thrombosis 和 Pulmonary Embolism 抗凝血劑的使用 Guideline

Deep Vein thrombosis VS Pulmonary embolism

• Distal leg DVT

• Severe symptoms：
• Treat with anticoagulants. 
• Length of treatment: 3 months (no matter whether DVT was associated with a transient risk factor (surgery, hospitalization, estrogen therapy, etc.) or was unprovoked (= idiopathic).
• No, mild or moderate symptoms：
• No anticoagulation needed.
• If DVT has extended: treat with anticoagulants for 3 months.
• If extension of clot has not occurred within the first 2 weeks, it is unlikely to occur subsequently. 
• Risk factors for extension: 
• Positive D-dimer, 
• DVT that is extensive or close to the proximal veins, 
• No reversible provoking factor for DVT present, 
• Active cancer, 
• Previous history of blood clots, and inpatient status.

• Proximal leg DVT

• Should be treated with anticoagulants.
• Not to use thrombolytics or clot removal interventions (thrombectomy) routinely.
• Treatment
• In the first few days：
• Use once daily Dalteparin (Fragmin) or Tinzaparin (Innohep) or Fondaparinux (Arixtra) or twice daily Enoxaparin (Lovenox).
• Beyond the first few days：
• warfarin, rather than Dabigatran (PradaxaÒ) or Rivaroxaban (XareltoÒ).
• Length of treatment with blood thinners:
  • DVT triggered by surgery: 
  • 3 months, rather than 6 or 12 months.
  • DVT due to a mild risk factor (i.e. non-surgical risk factors such as estrogen therapy, long-distance travel, non-surgical hospital stay, etc): 
  • 3 months, rather than 6 or 12 months or long-term.
  • Unprovoked (idiopathic) DVT: 
  • long-term, if risk for bleeding not very high. Re-evaluation every so often (once per year?) to determine whether long-term treatment is still the right thing to do.

• Incidentally discovered (asymptomatic) DVT or PE 

• Leg, pelvic or IVC DVT：
• Treat with blood thinners. Length: same as discussed in proximal and distal DVT section (discussed above).  
• Abdominal DVT (portal, splenic, mesenteric or hepatic vein thrombosis)：
• Do not treat with blood thinners. 
• PE：
• Treat with anticoagulants. Length: same as discussed in the PE section below.

• Pulmonary embolism

• Should be treated with anticoagulants.
•  tPA for 2 hours into a peripheral vein while
• PE is massive (i.e. combination of low blood pressure below 90 mm Hg systolic, heart rate above 100/min, poor perfusion of inner organs, low blood oxygen level, abnormal serum cardiac enzymes, abnormal right heart function on echo or CT) 
• The patient is at low risk for bleeding
• The first few days: 
• Use once daily Dalteparin (Fragmin) or Tinzaparin (Innohep) or Fondaparinux (Arixtra) or twice daily Enoxaparin (Lovenox).
• Beyond the first few days: 
• warfarin, rather than Dabigatran (PradaxaÒ) or Rivaroxaban (XareltoÒ).
• Length of treatment with blood thinners (same treatment decision principles as in DVT):
  • PE triggered by surgery: 
  • 3 months, rather than 6 or 12 months.
  • PE due to a mild risk factor (i.e. non-surgical risk factors such as estrogen therapy, long-distance travel, non-surgical hospital stay, etc): 
  • 3 months, rather than 6 or 12 months or long-term.
  • Unprovoked (idiopathic) PE:
  • Long-term, if risk for bleeding not very high. Re-evaluation every so often (once per year?) to determine whether long-term treatment is still the right thing to do.

• Cancer associated DVT or PE

  • Treat for at least 3 months and preferably long-term, unless bleeding risk very high.
  • Low molecular weight heparin is the preferred treatment, rather than warfarin.

• Arm DVT

  • In upper extremity DVT not associated with a central venous catheter: 
  • 3 months of anticoagulation is recommended.
  • In upper extremity DVT associated with a central venous catheter:
  • Anticoagulation should be given as long as the catheter is in place.
  • If the catheter is removed, anticoagulation should continue for 3 months 

• Superficial thrombophlebitis

• In patients with superficial thrombophlebitis of the leg of at least 5 cm in length：
• The suggestion is to give prophylactic dose of fondaparinux (preferred) or LMWH for 45 days, rather than no anticoagulation.

•  Vena cava filter (=IVC filter)

• Should only be placed in the patient with an acute DVT who cannot tolerate blood thinners because of active bleeding or a high risk for bleeding.
• Wear for at least 2 years (to prevent or minimize the occurrence of postthrombotic syndrome.
• If at 2 years the patient has bothersome symptoms of postthrombotic syndrome (swelling, pain), continue to wear stockings for symptoms relief.

• Compression stockings

• Wear for at least 2 years (to prevent or minimize the occurrence of postthrombotic syndrome.
• If at 2 years the patient has bothersome symptoms of postthrombotic syndrome (swelling, pain), continue to wear stockings for symptoms relief.

以上由ACCP提供

【超音波】RUSH EXAM - Rapid Ultrasound in SHock

Shock大致上分成四種：Hypovolemic、Cardiogenic、Distributive 和 Obstructive。然而要怎麼評估人體的水分是一門很大的學問!

Skin turgor、urine output、body weight可以簡單的評估，但是無法精確；
Central venous pressure.和Swan-Ganz可以嚴密監控，但是具侵入性，尤其Swan-Ganz在一篇2005年JAMA的paper被質疑其必要性(complication太多、弊多於利)。

因此，簡單、迅速、準確的體液評估方式，就在這個背景下產生~~~

以下歡迎我們的主角~~~RUSH

1.  How to Case Study ： RUSH Exam Video Part 1

2.  How to Case Study ： RUSH Exam Video Part 2

3.  How to Case Study ： RUSH Exam Video Part 3

https://www.youtube.com/watch?v=oXiIU4mx-H8

4.  How to Case Study ： RUSH Exam Video Part 4